Difference Between Active And Passive Immunity

Difference Between Active and Passive Immunity

Introduction on Active and Passive Immunity

Active immunity occurs when your own immune system generates a response—producing antibodies and memory cells after exposure to a pathogen or vaccine—providing long-term protection. In contrast, passive immunity is the transfer of pre-formed antibodies from another source, offering immediate but temporary protection.

Difference between Active and Passive Immunity:

Aspect	Active Immunity	Passive Immunity
Definition	Immunity developed when the body's own immune system produces antibodies in response to an antigen.	Immunity acquired by receiving pre-formed antibodies from an external source.
Source	Endogenous response following natural infection or vaccination.	Exogenously administered antibodies (e.g., maternal antibodies, immunoglobulin therapy, antivenoms).
Onset	Slow; takes days to weeks for the immune system to mount a response.	Immediate; protection is available as soon as antibodies are introduced.
Duration	Long-lasting; provides enduring protection with immunological memory.	Temporary; protection wanes as the transferred antibodies are metabolized or degraded.
Memory	Generates memory cells, ensuring a quicker and stronger response upon re-exposure.	Does not induce memory formation; each protection episode is short-lived.
Mechanism	Involves antigen recognition, clonal expansion of lymphocytes, and antibody production.	Involves direct neutralization or opsonization by pre-formed antibodies without activation of the host's B cells.
Examples	Vaccinations, recovery from infections such as measles or chickenpox.	Maternal antibodies passed through the placenta or breast milk, administration of antivenom or immunoglobulin therapy.
Advantages	Provides durable, long-term protection and can confer herd immunity.	Offers immediate protection for individuals who are at immediate risk or have compromised immune systems.
Limitations	Delayed onset leaves a window of vulnerability; requires time to develop effective immunity.	Temporary protection; repeated administrations may be necessary; no long-term immune memory is established.
Applications	Preventive measures such as vaccines and immunization programs.	Emergency treatments like post-exposure prophylaxis, passive immunization during outbreaks, or in immunocompromised patients.

Essential Study Materials for NEET UG Success

Study Materials for NEET 2025
S.No	Study Materials Links
1	NEET Revision Notes
2	NEET Important Questions
3	NEET Question Papers
4	NEET Sample Papers
5	NEET Syllabus
6	NEET Mock Test Series
7	NEET Formulas
8	NEET Difference Between
9	NEET Most Important Chapters
10	NEET Question and Answers
11	NEET UG Preparation Books
12	NEET Chapter-Wise Weightage

FAQs on Difference Between Active and Passive Immunity

1. What is the simple difference between active and passive immunity?

Active immunity is when your immune system produces its own antibodies after exposure to a pathogen or vaccine, while passive immunity is when you receive pre-made antibodies from an external source.

2. What is the difference between active and passive prevention?

Active prevention involves stimulating your immune system (e.g., through vaccination) to develop long-lasting protection, whereas passive prevention uses pre-formed antibodies to provide immediate, short-term protection.

3. What are passive immunity examples?

Examples include maternal antibodies transferred during pregnancy or through breast milk, immunoglobulin therapy, antivenoms, and monoclonal antibody treatments.

4. What is the difference between active and passive absorption?

Active absorption requires energy to transport substances across cell membranes (e.g., endocytosis), whereas passive absorption occurs by diffusion along a concentration gradient without energy input.

5. What is an example of an active immunity?

Receiving a vaccine is an example of active immunity, as it triggers your body to produce antibodies and memory cells against a specific pathogen.

6. How will you distinguish between active immunity and passive immunity?

Active immunity develops when your immune system responds to an antigen by creating antibodies and memory cells, while passive immunity is the transfer of pre-formed antibodies, offering immediate but temporary protection.

7. What is immunity and what are its types?

Immunity is the body's ability to resist infections. It is broadly divided into innate immunity (non-specific, immediate defense mechanisms) and adaptive immunity (specific responses that include active and passive immunity).

8. Are antibiotics passive immunity?

No, antibiotics are drugs used to treat bacterial infections; they do not provide immunity but rather kill or inhibit bacteria.

9. Is breast milk passive immunity?

Yes, breast milk provides passive immunity as it contains maternal antibodies that help protect infants against infections.

10. What are the four types of innate immunity?

The four types include physical barriers (e.g., skin, mucous membranes), chemical barriers (e.g., stomach acid, antimicrobial peptides), cellular defenses (e.g., phagocytes like macrophages and neutrophils), and the complement system.